Methylenediphosphonate esters

ABSTRACT

ARE DISCLOSED WHEREIN EACH R IS A HYDROCARBYL RADICAL CONTAINING FROM 7 TO 22 CARBON ATOMS AND IS SELECTED FROM THE GROUP CONSISTING OF ALKYL, ARYL, ALKARYL, ARALKYL, ALKENYL, HALOALKYL, HALOARYL, HALOALKARYL, HALOARALKYL, HALOALKENYL AND NITROARYL GROUPS. THE COMPOUNDS ARE USEFUL AS EXTREME PRESSURE AND ANTI-WEAR ADDITIVES IN LUBRICANT COMPOSITIONS.   CH2(-P(=O)(-O-R)2)2   METHYLENE DIPHOSPHONATE ESTERS OF THE FORMULA

United States Patent O 3,705,219 METHYLENEDIPHOSPHONATE ESTERS Denzel Allan Nicholson, Springfield Township, Hamilton County, Ohio, assignor to The Procter 81 Gamble Company, Cincinnati, Ohio No Drawing. Continuation-impart of application Ser No. 770,860, Oct. 25, 1968. This application Dec. 20, 1968, Ser. No. 785,741

Int. Cl. C07f 9/40 US. Cl. 260-932 2 Claims ABSTRACT OF THE DISCLOSURE Methylene diphosphonate esters of the formula Pom,

II 03R,

are disclosed wherein each R is a hydrocarbyl radical containing from 7 to 22 carbon atoms and is selected from the group consisting of alkyl, aryl, alkaryl, aralkyl, alkenyl, haloalkyl, haloaryl, haloalkaryl, haloaralkyl, haloalkenyl and nitroaryl groups. The compounds are useful as extreme pressure and anti-wear additives in lubricant compositions.

CROSS-REFERENCE This application is a continuation-in-part of the copending application of Denzel Allan Nicholson, Ser. No. 770,- 860, filed Oct. 25, 1968, for Process for the Production of Halogenated Methylenediphosphonates, Malonates and Phosphonoacetates, now US. Patent 3,662,039, issued May 9, 1972.

FIELD OF THE INVENTION This invention relates to novel tetrahydrocarbyl methylenediphosphonate esters, wherein the hydrocarbyl groups have from 7 to 22 carbon atoms, which are useful as anti- Wear additives in lubricant compositions and as extreme pressure additives in lubricant compositions wherein the Wear and load-bearing properties of lubricant compositions containing these novel methylenediphosphonate esters are improved.

PRIOR ART The methylenediphosphonate esters wherein the alkyl groups have from 1 to 6 carbon atoms are known compounds useful as intermediates in the preparation of watersoluble builders for use in detergent compositions, as disclosed by Francis L. Diehl in U .8. Patent 3,213,030. Various processes for the preparation of these short chain methylenediphosphonates are well known and have been described in the art. [See J. A. Walmsley and S. Y. Tyree, Inorg. Chem., 2,312 (1963), and T. H. Siddall, III, and C. A. Prokuska, Inorg. Chem, 4, 783 (1965)]. In addition the preparation of the halogenated methylenediphosphate esters has been described in the copending application of Oscar T. Quimby and James B. Prentice, Ser. No. 770,782, filed Oct. 25, 1968, and by Denzel Allan Nichlson, Ser. No. 770,860, filed Oct. 25, 1968. The prior art does not, however, disclose the unhalogenated long chain tetrahydrocarbyl methylenediphosphonate esters, wherein the hydrocarbyl groups have from 7 to 22 carbon atoms, having effectiveness as anti-wear additives and extreme pressure additives in lubricant compositions.

Accordingly, it is an object of this invention to provide a novel class of methylenediphosphonate esters. In addition it is an object of this invention to provide a novel class of tetrahydrocarbyl methylenediphosphonate esters wherein the hydrocarbyl groups have from 7 to 22 carbon 3,75,219 Patented Dec. 5, 1972 SUMMARY OF THE INVENTION This invention relates to a novel class of tetrahydrocarbyl methylenediphosphonate esters of the formula POaRg 1303B: wherein each R is selected from the group consisting of alkyl, aryl, alkaryl, aralkyl, alkenyl, haloalkyl, haloaryl, haloalkaryl, haloaralkyl, haloalkenyl and nitroaryl groups having from 7 to 22 carbon atoms. The above described long-chain methylenediphosphonate esters have utility as extreme pressure and anti-wear additives in lubricant compositions as disclosed in the copending application of Robert Earl Wann, Denzel Allan Nicholson, and Ted Joe Logan, Ser. No. 762,966, filed Sept. 26, 1968, for Lubricant Composition, now U.S. Patent 3,579,449 issued May 18, 1971. This application is incorporated herein by reference.

DESCRIPTION OF THE INVENTION The tetrahydrocarbyl methylenediphosphonate esters of this invention have the formula H- I -H Pom,

wherein each R is a hydrocarbyl group selected from the group consisting of alkyl, aryl, alkaryl, aralkyl, alkenyl, haloalkyl, haloaryl, haloalkaryl, haloaralkyl, haloalkenyl and nitroaryl groups having from 7 to 22 carbon atoms.

As has been hereinbefore described, R in the above formula is a hydrocarbyl group such as those described above. R in the above formula may be the same or different. Suitable examples of these hydrocarbyl groups and the resulting tetrahydrocarbyl methylenediphosphonate esters are shown in greater detail in the following table.

HexadeeyL. Tetrahexadecyl methylenediphosphonate.

Tetraheptadeeyl methylenediphosphonate. Tetraoetadecyl methylenediphosphonate. Tetranonadeeyl methylenedlphosphonate.

Tetraeicosyl methylenediphosphonate.

Docosyl Tetradocosyl methylenediphosphonate.

Aryl group Tetraaryl methylenedlphosphonate Naphthyl Tetranaphthyl methyleuediphosphonate.

BiphenyL. Tetrabiphenyl methylenediphosphonate.

Tetraphenanthryl methylenediphosphouate. Anthracyl Tetraauthracyl methylenediphosphonate.

phonate.

TABLE I-Contlnued Heptenyl Tetraheptenyl methylenediphosphonate.

Deeenyl Tetradecenyl Inethylonediphosphonate.

3,6-dodecadienyl Tetga-Bfi-dodecadienyl methylenediphosp onate.

Linolenyl Tetralinolenyl methylenediphosphonate.

Oleyl Tetraoleyl methyleuediphosphonate.

Linoleyl Tetralinoleyl methylenediphosphonate.

Haloaklyl group Tetrahaloalkyl methylenediphosphonate 7-chlorohexyl... Tetra-7-chlorohexyl methylenodiphosphonate.

IO-bromododecyl Tetga-lO-bromododecyl methylenediphosp onate.

-iod0pentadecy1 Tetga-lfi-lodopentadeeyl Inethylenediphosp onate.

-brornoeicosyl Tetlra-w-bromoeicosyl methylenediphosonate.

6,17-dichloroheptadecyl Tetra-6,17-dlchloroheptadecylmethylenediphosphonate.

9-fluoron0nyl Tctga-Q-fluorononyl methylenedlphosp onate.

5-bromo-5-methyldeeyL Tetra-5-bromo-5 methyldecyl methylenediphosphonate.

4-cl1loronaphthyl Tetfiai-chloronaphthyl methylenediphosp onate.

4-bromoblphenyl Tetra-4-br0mob1phenyl methylenediphosphonate.

Haloalkaryl group Tetrahaloalkaryl mothylenediphosphonate (Chloromethyl)pl1enyl Tetra(chloromethyDphenyl methylenediphosphonate.

(BromoethyDphenyl Tetra(bromoethyl) phenyl methylenedlphosphonate.

4-(iodoethy1)-naphthyl. Tetrat-(iodoethylnaphthyl methylenedlphosphonate.

4-( 10, lo-dichlorodecyl) Tetrawl-(10,lo-dichlorodecyl) naphthyl methnaphthyl. ylenediphosphonate.

As has hereinbefore been described, mixtures of the above hydrocarbyl groups are suitable, e.g., heptyl-pchlorobenzyldistearyl methylenediphosphonate.

All of the tetrahydrocarbyl methylenediphosphonates described in the second column of Table 1 above are effective anti-wear additives and extreme pressure additives when used in a lubricant composition at the 5% level in, e.g., a Kendall-base SAE oil as disclosed in the Wann et a1. application, supra. The C C esters are especially effective anti-wear additives, being more effective as anti wear additives than heretofore known anti-wear additives, e.g., tricresyl phosphate.

PREPARATION OF THE TETRAHYDROCARBYL METHYLENEDIPHOSPHONATES The tetrahydrocarbyl methylenediphosphonate esters of this invention can be prepared simply by the reaction of methylenediphosphonic acid with a trihydrocarbyl orthoforrnate according to the following equation:

(I) H2031 CHzP 03112 4HC(OR); --r

l RzOaP CHzP 03R: 4ROH 4HCOR wherein R is as above defined. The trihydrocarbyl orthoformate esters are commercially available or can be prepared by reacting the appropriate hydrocarbyl alcohol with HCN according to the following:

The methylenediphosphonic acids used in Equation I above can be prepared according to the following: a tetraiso propyl methylendiphosphonate ester can be prepared by reacting dibromomethane with tri-iso-propyl phosphite according to the following reaction:

The tri-iso-propyl phosphite used in the above reaction can be derived from iso-propyl alcohol and phosphorus trichloride. The dibromomethane is a high temperature reaction product of methane and bromine. A more detailed 0 discussion of this synthesis of the tetra-iso-propyl methylenediphosphonate esters appears in US. patent application of Clarence H. Roy, Novel Compounds, Ser. No. 266,055, filed Mar. 18, 1963. The tetra-iso-propyl methyenediphosphonate is subsequently pyrolyzed at a temperature of from about 150 C. to about 225 C. according to the pyrolysis method described by Canavan et aL, J. Chem. Soc. (1962), pp. 331-4, to obtain the methylenediphosphonic acid. The methylenediphosphonic acid obtained according to the above procedure is then reacted with the trihydrocarbyl orthoformate ester according to Equation I above to obtain the tetrahydrocarbyl methylenediphosphonate ester. Other methods of preparation of the tetramethylenediphosphonate esters are given in the examples hereinafter and will also be apparent to one skilled in the art.

In the preparation of the tetrahydrocarbyl methylenediphosphonates of this invention, a mixture of the methylenediphosphonic acid and the trihydrocarbyl orthoformate is prepared in a molar ratio of from about 1:4 to about 1:20 of the acid to the orthoformate, preferably from about 1:4 to about 1:45. No solvent is necessary in the reaction described by Equation I above since the orthoformate not only acts as a reactant but also as a solvent in the reaction mixture. An inert solvent, however, may also be used where desired in addition to the ortho formate. Suitable such solvents are butyl cellosolve and n-propylsulfone. Where an added inert solvent is used it will generally be used in a weight ratio of about 1:1 to about 50:1 to the methylenediphosphonic acid, preferably from about 10:1 to about 20:1.

The reaction mixture containing the methylenediphosphonic acid, the trihydrocarbyl orthoforrnate, and the inert solvent, if used, is then warmed to a temperature of from about C. to about 150 0, preferably from about C. to about C. for from about 10 minutes to about 6 hours. The hydrocarbyl alcohol and the hydrocarbyl formate formed in the reaction are distilled off to drive the reaction to completion (e.g., toward the right side of Equation I above) to obtain the tetrahydr0- carbyl methylenediphosphonate ester. It will be apparent to one skilled in the art that where an inert solvent is used the one chosen should have a boiling point higher than the boiling point of the hydrocarbyl alcohol and hydrocarbyl formate formed in the reaction so that the reaction can be driven to completion without loss of the solvent. An inert solvent having a boiling point about 20 C. higher than the boiling of the hydrocarbyl alcohol and hydrocarbyl formate is preferred. The tetrahydrocarbyl methylenediphosphonate ester formed can be purified additionally where desired by conventional techniques, e.g., fractional distillation, fractional crystallization, column chromatography, and crystallization of metal salt adducts.

Example I.-Preparation of tetradecyl methylenediphosphonate A one liter reaction flask was charged with 22 g. (0.125 mole) of methylenediphosphonic acid and 242 g. (0.5 mole) of tridecyl orthoformate. The pressure inside the reaction flask was reduced to 33 mm. Hg by means of an aspirator and the flask was heated to 120 C. As the reaction proceeded decyl alcohol and decyl formate was distilled off, and 95% of the theoretical amounts of these materials was collected. The pressure was then lowered to 0.05 mm. Hg to remove any traces of unreacted orthoformate. A P NMR spectrum of the material in the reaction flask indicated it to be nearly pure tetradecyl methylenediphosphonate, 8= 19.0 p.p.m.

Example II.-Preparation of tetrastearyl methylenediphosphonate A one liter reaction flask was charged with 22 g. (0.125 mole) of methylenediphosphonic acid and 410 g. (0.5 mole) of tristearyl orthoformate. The flask was then heated to 130 C. while a vacuum of 0.5 mm. Hg was applied. Stearyl alcohol and stearyl formate were collected as they distilled over; 86% of the theoretical amounts of these products was obtained. The remaining material in the flask was dissolved in a 1:4 mixture of petroleum ether/hexane which had been heated to reflux. Upon cooling, tetrastearyl methylenediphonate crystallized out, M.P. 60-62". This product was shown to be pure by P NMR analysis 6=19.5 ppm. (O=85% H, P

When in above examples, other trihydrocarbyl orthoformates are substituted on a molar basis for the tridecyl orthoformate used in Example I or for the tristearyl orthoformate used in Example II, substantially equivalent results are obtained in that the corresponding tetrahydrocarbyl methylenediphosphonates are formed: e.g., triheptyl orthoformate to produce tetraheptyl methylenediphosphonate; trinaphthyl orthoformate to produce tetranaphthyl methylenediphosphonate; trimethylphenyl orthoformate to produce tetramethylphenyl methylenediphosphonate; tribenzyl orthoformate to produce tetrabenzyl methylenediphosphonate; triheptenyl orthoformate to produce tetraheptenyl methylenediphosphonate; tri-7- chlorohexyl orthoformate to produce tetra-7-chlorohexyl methylenediphosphonate; tri-4-chloronaphthyl orthoforformate to produce tetr-a-4-chloronaphthyl methylenediphosphonate; tri(chloromethyl)phenyl orthoformate to produce tetra(chloromethyl)phenyl methylenediphosphonate; tri-p-ch-lorobenzyl orthoformate to produce tetra-pchlorobenzyl methylenediphosphonate; tri-7-chlorohept-2- enyl orthoformate to produce tetra-7-chlorohept-2-enyl methylenediphosphonate; and tri-p-nitrobenzyl orthoformate to produce tetra-p-nitrobenzyl methylenediphosphonate.

When in Example I and II above an inert solvent such as butyl Cellosolve or n-propyl sulfone in addition is used in a weight ratio of 1:1 to 50:1 to the methylenediphosphonic acid, substantially equivalent results are obtained in that tetradecyl methylenediphosphonate and tetr-astearyl methylenediphosphonate, respectively, are obtained.

Example III.-Preparation of tetraoctyl methylenediphosphonate An aqueous solution of 0.1 mole of methylenediphosphonyl tetrachloride [prepared according to the method of H. R. Hays and T. J. Logan, J. Org. Chem, 31, 3391 (1966))] and 0.4 mole of quinoline is slowly combined with 0.4 mole of l-octanol. The reaction temperature is maintained at 50-70 C. during the addition. After all heat evolution has ceased, 500 cc. of water are added and this two phase mixture is extracted 3 times with cc. portions of CHCl The organic layers are combined, dried over anhydrous Na SO and the CHCl removed by flash evaporation. The resulting liquid is substantially pure tetraoctyl methylenediphosphonate.

When in Example III above, other hydrocarbyl alcohols are substituted on a molar basis for the l-octanol used, substantially equivalent results are obtained in that the corresponding tetrahydrocarbyl methylenediphosphonates are formed: e.g., heptyl alcohol, nonyl alcohol, decyl alcohol, dodecyl alcohol, pentadecyl alcohol, hexadecyl alcohol, eicosyl alcohol, docosyl alcohol, naphthyl alcohol, methylphenyl alcohol, benzyl alcohol, heptenyl alcohol, 7-chlorohexyl alcohol, 4-chloronaphthyl alcohol, (chloromethyl)phenyl alcohol, p-chlorobenzyl alcohol, 7-chloro hept-Z-enyl alcohol, p-m'trobenzyl alcohol to produce tetraheptyl methylenediphosphonate, tetranonyl methylenediphosphonate, tetradecyl methylenediphosphonate, tetradodecyl methylenediphosphonate, tetrapentadecyl methylenediphosphonate, tetrahexadecyl methylenediphosphonate, tetraeicosyl methylenediphosphonate, tetradocosyl methylenediphosphonate, tetranaphthyl methylenediphosphonate, tetramethylphenyl methylenediphosphonate, tetrabenzyl methylenediphosphonate, tetraheptenyl methylenediphosphonate, tetra-7-chlorohexyl methylenediphosphonate, tetra-4-chloronaphthyl methylenediphosphonate, tetra(chloromethyl)phenyl methylenediphosphonate, tetra p chlorobenzyl methylenediphosphonate, tetra 7 chloro-hept-Z-enyl methylenediphosphonate, tetra-p-nitrobenzyl methylenediphosphonate, respectively.

The tetrahydrocarbyl methylenediphosphonates disclosed in Examples I-III above are useful as extreme pressure additives and anti-wear additives when used in lubricant compositions, for example, at the 5% level in a Kendall-base SAE 30 mineral oil.

What is claimed is:

1. A tetrahydrocarbyl methylenediphosphonate ester of the formula wherein each R is selected from the group consisting of nitroaryl haloalkyl, and haloalkenyl groups having from 7 to 22 carbon atoms.

2. The ester of claim 1 wherein each R is haloalkyl.

References Cited UNITED STATES PATENTS 3,299,123 1/ 1967 Fitch et a1. 260-9'32 X 3,251,907 5/1966 Roy 260932 X 3,256,370 6/1966 Fitch et a1. 260932 X 3,471,552 10/ 1969 Budnick 260-932 X 3,255,145 6/1966 Graham 260-932 3,579,449 5/1971 Wann et a1. 260-932 X LEWIS GOTIS, Primary Examiner R. L. RAYMOND, Assistant Examiner US. Cl. X.R. 

